The inaugural CNBC Upstart 25: Promising young start-ups

The inaugural Upstart 25, CNBC's first-ever list of promising young start-ups, features a diverse group of companies that are building brands and breaking industry barriers on the path to becoming tomorrow's household names.

These entrepreneurial success stories are scaling quickly, growing user base and sales and attracting initial rounds of funding. There's always focus on the billion-dollar-plus unicorns, but there is more investment activity taking place among younger start-ups. Angel/seed capital reached $6.6 billion in 2016, according to PitchBook. In the past two years, early VC funding reached a decade high.

Antibiotic-resistance infections are on the rise globally, resulting in a major health crisis. SciBac, a Silicon Valley start-up backed by Peter Thiel's Breakout Labs, has invented a microbiome pill to tackle superbugs.